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Lesson 3 The subject approach to database design
Objective Describe the subject approach to database design.

Subject Approach to Database Design

In general, there are two ways to approach database design.
  1. One is to focus on the subject matter with which the database is concerned, for example, how it will be organized and displayed;
  2. the other is to focus on the application in which the database will be created and viewed.

Store Data according to Subject Matter

In the subject approach to database design, all the tables in a database store data according to subject matter. A large company, for example, might have a database devoted to the sales department. Such a database might have tables devoted to customers, orders, discounts, and so forth. Other databases in the same company might be devoted to personnel, accounting, marketing, etc.

The Subject Approach

Just as each table in a database is devoted to one specific subject, in the subject approach multiple tables in a database relate to a single subject area. The subject approach to database design is an approach that focuses on organizing data according to the specific subjects or topics that the data represents. This approach is also known as the entity-centered or data-centered approach. In the subject approach, the database is designed around the specific data entities that need to be stored, such as customers, products, orders, or employees. Each entity is defined by its attributes or properties, such as name, address, phone number, or email, which are stored in the corresponding fields or columns in the database.
The subject approach emphasizes the importance of data normalization, which is the process of organizing data in a way that minimizes redundancy and inconsistency. This involves breaking down data into smaller, more atomic pieces, and creating separate tables for related entities, such as customers and orders. By doing so, the subject approach can help ensure data integrity and improve data quality. The subject approach is commonly used in relational database design, where data is organized into tables and related through common attributes or keys. However, other database models, such as hierarchical or network databases, may also use the subject approach.
The subject approach to database design emphasizes the importance of organizing data around the specific subjects or topics that the data represents, rather than around specific applications or processes. This can help ensure a more flexible and adaptable database design that can be easily modified or extended as needed.

Top-down Design

The subject approach to database design is called a top-down design because it follows the four-step order.

Top Down Design
Even if you were designing a database for a small company, the subject approach would dictate that you create three small databases if you identified three distinct subject areas.
The next lesson introduces the application approach to database design.

Before moving on to the next lesson, click the link below to check your understanding of the subject approach to database design.
Designing Subject Database

Relational Database Design